I. Reference to Existing Wind Mills
All windmills known at present have been designed under the principles of the propeller theory, according to which one can only utilize a small part of the horizontal vector of the force of the wind, that is, its very small perpendicular component. This component has to raise the weights of the vanes and make them turn around with a force capable of producing energy. Therefore, the efficiency of these kinds of mills is very poor. They can only work best when the pressure of the wind is very strong, with the result of a KW with a very high cost. Besides, there are strong winds only in a few places, and for this reason, the use of these kinds of mills is actually limited to certain areas, such as California, Holland and Tarifa (Spain). In the rest of the World, windmills practically do not exist. In short, the propeller design is a far from perfect system.